Multiwell plate assemblies are known in the prior art which are commonly used for bioassays. Each multiwell plate assembly includes a multiwell plate body having an array of wells formed therein, typically having 96, 384, or 1,536 wells. Because of the commonplace use of multiwell plate bodies, standard dimensions of the plates have been developed to facilitate use with pick-and-place machines. Each well is cup-shaped and accommodates various chemical and/or biological fluids and matters in conducting parallel bioassays, such as with parallel drug screening.
In certain instances, it is desired to minimize, if not prevent, contamination of the bioassays from external sources, as well as, intermixing of the fluids/matters of the various wells. To this end, various techniques have been developed to seal the wells, including providing an emplaceable lid atop the multiwell plate body, and/or adhering a thin film across the open ends of the wells. These prior art techniques, however, suffer from several drawbacks, including having an excessively-loose seal provided by the emplaceable lid, and/or requiring adhesion of a film.